Synnefo » Pithos MS Client

using System;

using System.Collections.Generic;

using System.ComponentModel.Composition;

using System.Data.SQLite;

using System.Diagnostics;

using System.Diagnostics.Contracts;

using System.IO;

using System.Linq;

using System.Threading;

using System.Threading.Tasks;

using Castle.ActiveRecord;

using Castle.ActiveRecord.Framework.Config;

using Pithos.Interfaces;

using Pithos.Network;

using log4net;

namespace Pithos.Core.Agents

{

    [Export(typeof(IStatusChecker)),Export(typeof(IStatusKeeper))]

    public class StatusAgent:IStatusChecker,IStatusKeeper

    {

        [System.ComponentModel.Composition.Import]

        public IPithosSettings Settings { get; set; }

        private Agent<Action> _persistenceAgent;

        private static readonly ILog Log = LogManager.GetLogger("StatusAgent");

        public StatusAgent()

        {            

            var appDataPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);

            _pithosDataPath = Path.Combine(appDataPath , "Pithos");

            if (!Directory.Exists(_pithosDataPath))

                Directory.CreateDirectory(_pithosDataPath);

            var source = GetConfiguration(_pithosDataPath);

            ActiveRecordStarter.Initialize(source,typeof(FileState),typeof(FileTag));

            ActiveRecordStarter.UpdateSchema();

            if (!File.Exists(Path.Combine(_pithosDataPath ,"pithos.db")))

                ActiveRecordStarter.CreateSchema();

        }        

        private static InPlaceConfigurationSource GetConfiguration(string pithosDbPath)

        {

            if (String.IsNullOrWhiteSpace(pithosDbPath))

                throw new ArgumentNullException("pithosDbPath");

            if (!Path.IsPathRooted(pithosDbPath))

                throw new ArgumentException("path must be a rooted path", "pithosDbPath");

            Contract.EndContractBlock();

            var properties = new Dictionary<string, string>

                                 {

                                     {"connection.driver_class", "NHibernate.Driver.SQLite20Driver"},

                                     {"dialect", "NHibernate.Dialect.SQLiteDialect"},

                                     {"connection.provider", "NHibernate.Connection.DriverConnectionProvider"},

                                     {

                                         "proxyfactory.factory_class",

                                         "NHibernate.ByteCode.Castle.ProxyFactoryFactory, NHibernate.ByteCode.Castle"

                                         },

                                 };

            var connectionString = String.Format(@"Data Source={0}\pithos.db;Version=3;Enlist=N", pithosDbPath);

            properties.Add("connection.connection_string", connectionString);

            var source = new InPlaceConfigurationSource();                        

            source.Add(typeof (ActiveRecordBase), properties);

            source.SetDebugFlag(false);            

            return source;

        }

        public void StartProcessing(CancellationToken token)

        {

            _persistenceAgent = Agent<Action>.Start(queue =>

            {

                Action loop = null;

                loop = () =>

                {

                    var job = queue.Receive();

                    job.ContinueWith(t =>

                    {

                        var action = job.Result;

                        try

                        {

                            action();

                        }

                        catch (SQLiteException ex)

                        {

                            Log.ErrorFormat("[ERROR] SQL \n{0}", ex);

                        }

                        catch (Exception ex)

                        {

                            Log.ErrorFormat("[ERROR] STATE \n{0}", ex);

                        }

// ReSharper disable AccessToModifiedClosure

                        queue.DoAsync(loop);

// ReSharper restore AccessToModifiedClosure

                    });

                };

                loop();

            });

        }

        public void Stop()

        {

            _persistenceAgent.Stop();            

        }

        public void ProcessExistingFiles(IEnumerable<FileInfo> existingFiles)

        {

            if(existingFiles  ==null)

                throw new ArgumentNullException("existingFiles");

            Contract.EndContractBlock();

            //Find new or matching files with a left join to the stored states

            var fileStates = FileState.Queryable;

            var currentFiles=from file in existingFiles

                      join state in fileStates on file.FullName.ToLower() equals state.FilePath.ToLower() into gs

                      from substate in gs.DefaultIfEmpty()

                               select new {File = file, State = substate};

            //To get the deleted files we must get the states that have no corresponding

            //files. 

            //We can't use the File.Exists method inside a query, so we get all file paths from the states

            var statePaths = (from state in fileStates

                             select new {state.Id, state.FilePath}).ToList();

            //and check each one

            var missingStates= (from path in statePaths

                                where !File.Exists(path.FilePath) && !Directory.Exists(path.FilePath)

                               select path.Id).ToList();

            //Finally, retrieve the states that correspond to the deleted files            

            var deletedFiles = from state in fileStates 

                        where missingStates.Contains(state.Id)

                        select new { File = default(FileInfo), State = state };

            var pairs = currentFiles.Union(deletedFiles);

            foreach(var pair in pairs)

            {

                var fileState = pair.State;

                var file = pair.File;

                if (fileState == null)

                {

                    //This is a new file

                    var fullPath = pair.File.FullName.ToLower();

                    var createState = FileState.CreateForAsync(fullPath, BlockSize, BlockHash);

                    createState.ContinueWith(state => _persistenceAgent.Post(state.Result.Create));

                }                

                else if (file == null)

                {

                    //This file was deleted while we were down. We should mark it as deleted

                    //We have to go through UpdateStatus here because the state object we are using

                    //was created by a different ORM session.

                    _persistenceAgent.Post(()=> UpdateStatusDirect(fileState.Id, FileStatus.Deleted));                    

                }

                else

                {

                    //This file has a matching state. Need to check for possible changes

                    var hashString = file.CalculateHash(BlockSize,BlockHash);

                    //If the hashes don't match the file was changed

                    if (fileState.Checksum != hashString)

                    {

                        _persistenceAgent.Post(() => UpdateStatusDirect(fileState.Id, FileStatus.Modified));

                    }                    

                }

            };            

        }

        private int UpdateStatusDirect(Guid id, FileStatus status)

        {

            using (log4net.ThreadContext.Stacks["StatusAgent"].Push("UpdateStatusDirect"))

            {

                try

                {

                    using (var connection = GetConnection())

                    using (

                        var command = new SQLiteCommand("update FileState set FileStatus= :fileStatus where Id = :id  ",

                                                        connection))

                    {                                                

                        command.Parameters.AddWithValue("fileStatus", status);

                        command.Parameters.AddWithValue("id", id);

                        var affected = command.ExecuteNonQuery();

                        return affected;

                    }

                }

                catch (Exception exc)

                {

                    Log.Error(exc.ToString());

                    throw;

                }

            }

        }

        private int UpdateStatusDirect(string path, FileStatus status)

        {

            using (log4net.ThreadContext.Stacks["StatusAgent"].Push("UpdateStatusDirect"))

            {

                try

                {

                    using (var connection = GetConnection())

                    using (

                        var command =

                            new SQLiteCommand("update FileState set FileStatus= :fileStatus where FilePath = :path ",

                                              connection))

                    {

                        command.Parameters.AddWithValue("fileStatus", status);

                        command.Parameters.AddWithValue("path", path.ToLower());

                        var affected = command.ExecuteNonQuery();

                        return affected;

                    }

                }

                catch (Exception exc)

                {

                    Log.Error(exc.ToString());

                    throw;

                }

            }

        }

        private int UpdateStatusDirect(string absolutePath, FileStatus fileStatus, FileOverlayStatus overlayStatus)

        {

            using (log4net.ThreadContext.Stacks["StatusAgent"].Push("UpdateStatusDirect"))

            {

                try

                {

                    using (var connection = GetConnection())

                    using (

                        var command =

                            new SQLiteCommand(

                                "update FileState set OverlayStatus= :overlayStatus, FileStatus= :fileStatus where FilePath = :path  ",

                                connection))

                    {

                        command.Parameters.AddWithValue("path", absolutePath.ToLower());

                        command.Parameters.AddWithValue("fileStatus", fileStatus);

                        command.Parameters.AddWithValue("overlayStatus", overlayStatus);

                        var affected = command.ExecuteNonQuery();

                        return affected;

                    }

                }

                catch (Exception exc)

                {

                    Log.Error(exc.ToString());

                    throw;

                }

            }

        }

        public string BlockHash { get; set; }

        public int BlockSize { get; set; }

        public void ChangeRoots(string oldPath, string newPath)

        {

            if (String.IsNullOrWhiteSpace(oldPath))

                throw new ArgumentNullException("oldPath");

            if (!Path.IsPathRooted(oldPath))

                throw new ArgumentException("oldPath must be an absolute path", "oldPath");

            if (string.IsNullOrWhiteSpace(newPath))

                throw new ArgumentNullException("newPath");

            if (!Path.IsPathRooted(newPath))

                throw new ArgumentException("newPath must be an absolute path", "newPath");

            Contract.EndContractBlock();

            FileState.ChangeRootPath(oldPath,newPath);

        }

        private PithosStatus _pithosStatus=PithosStatus.InSynch;       

        public void SetPithosStatus(PithosStatus status)

        {

            _pithosStatus = status;

        }

        public PithosStatus GetPithosStatus()

        {

            return _pithosStatus;

        }

        private readonly string _pithosDataPath;

        public FileState GetStateByFilePath(string path)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");

            Contract.EndContractBlock();

            try

            {

                using (var connection = GetConnection())

                using (var command = new SQLiteCommand("select Id, FilePath, OverlayStatus,FileStatus ,Checksum   ,Version    ,VersionTimeStamp,IsShared   ,SharedBy   ,ShareWrite  from FileState where FilePath=:path", connection))

                {

                    command.Parameters.AddWithValue("path", path.ToLower());

                    using (var reader = command.ExecuteReader())

                    {

                        if (reader.Read())

                        {

                            //var values = new object[reader.FieldCount];

                            //reader.GetValues(values);

                            var state = new FileState

                                            {

                                                Id = reader.GetGuid(0),

                                                FilePath = reader.IsDBNull(1)?"":reader.GetString(1),

                                                OverlayStatus =reader.IsDBNull(2)?FileOverlayStatus.Unversioned: (FileOverlayStatus) reader.GetInt64(2),

                                                FileStatus = reader.IsDBNull(3)?FileStatus.Missing:(FileStatus) reader.GetInt64(3),

                                                Checksum = reader.IsDBNull(4)?"":reader.GetString(4),

                                                Version = reader.IsDBNull(5)?default(long):reader.GetInt64(5),

                                                VersionTimeStamp = reader.IsDBNull(6)?default(DateTime):reader.GetDateTime(6),

                                                IsShared = !reader.IsDBNull(7) && reader.GetBoolean(7),

                                                SharedBy = reader.IsDBNull(8)?"":reader.GetString(8),

                                                ShareWrite = !reader.IsDBNull(9) && reader.GetBoolean(9)

                                            };

/*

                            var state = new FileState

                                            {

                                                Id = (Guid) values[0],

                                                FilePath = (string) values[1],

                                                OverlayStatus = (FileOverlayStatus) (long)values[2],

                                                FileStatus = (FileStatus) (long)values[3],

                                                Checksum = (string) values[4],

                                                Version = (long?) values[5],

                                                VersionTimeStamp = (DateTime?) values[6],

                                                IsShared = (long)values[7] == 1,

                                                SharedBy = (string) values[8],

                                                ShareWrite = (long)values[9] == 1

                                            };

*/

                            return state;

                        }

                        else

                        {

                            return null;

                        }

                    }                    

                }

            }

            catch (Exception exc)

            {

                Log.ErrorFormat(exc.ToString());

                throw;

            }            

        }

        public FileOverlayStatus GetFileOverlayStatus(string path)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");

            Contract.EndContractBlock();

            try

            {

                using (var connection = GetConnection())

                using (var command = new SQLiteCommand("select OverlayStatus from FileState where FilePath=:path", connection))

                {

                    command.Parameters.AddWithValue("path", path.ToLower());

                    var s = command.ExecuteScalar();

                    return (FileOverlayStatus) Convert.ToInt32(s);

                }

            }

            catch (Exception exc)

            {

                Log.ErrorFormat(exc.ToString());

                return FileOverlayStatus.Unversioned;

            }

        }

        private string GetConnectionString()

        {

            var connectionString = String.Format(@"Data Source={0}\pithos.db;Version=3;Enlist=N;Pooling=True", _pithosDataPath);

            return connectionString;

        }

        private SQLiteConnection GetConnection()

        {

            var connectionString = GetConnectionString();

            var connection = new SQLiteConnection(connectionString);

            connection.Open();

            using(var cmd =connection.CreateCommand())

            {

                cmd.CommandText = "PRAGMA journal_mode=WAL";

                cmd.ExecuteNonQuery();

            }

            return connection;

        }

        public void SetFileOverlayStatus(string path, FileOverlayStatus overlayStatus)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted","path");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() => FileState.StoreOverlayStatus(path.ToLower(),overlayStatus));

        }

       /* public void RenameFileOverlayStatus(string oldPath, string newPath)

        {

            if (String.IsNullOrWhiteSpace(oldPath))

                throw new ArgumentNullException("oldPath");

            if (!Path.IsPathRooted(oldPath))

                throw new ArgumentException("The oldPath must be rooted", "oldPath");

            if (String.IsNullOrWhiteSpace(newPath))

                throw new ArgumentNullException("newPath");

            if (!Path.IsPathRooted(newPath))

                throw new ArgumentException("The newPath must be rooted", "newPath");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() =>FileState.RenameState(oldPath, newPath));

        }*/

        public void SetFileState(string path, FileStatus fileStatus, FileOverlayStatus overlayStatus)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");

            Contract.EndContractBlock();

            Debug.Assert(!path.Contains(FolderConstants.CacheFolder));

            Debug.Assert(!path.EndsWith(".ignore"));

            _persistenceAgent.Post(() => UpdateStatusDirect(path.ToLower(), fileStatus, overlayStatus));

        }

/*

        public void StoreInfo(string path,ObjectInfo objectInfo)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");            

            if (objectInfo == null)

                throw new ArgumentNullException("objectInfo", "objectInfo can't be empty");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() =>

            {

                var filePath = path.ToLower();

                //Load the existing files state and set its properties in one session            

                using (new SessionScope())

                {

                    //Forgetting to use a sessionscope results in two sessions being created, one by 

                    //FirstOrDefault and one by Save()

                    var state =FileState.FindByFilePath(filePath);

                    //Create a new empty state object if this is a new file

                    state = state ?? new FileState();

                    state.FilePath = filePath;

                    state.Checksum = objectInfo.Hash;

                    state.Version = objectInfo.Version;

                    state.VersionTimeStamp = objectInfo.VersionTimestamp;

                    state.FileStatus = FileStatus.Unchanged;

                    state.OverlayStatus = FileOverlayStatus.Normal;

                    //Do the save

                    state.Save();

                }

            });

        }

*/

        public void StoreInfo(string path, ObjectInfo objectInfo)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");

            if (objectInfo == null)

                throw new ArgumentNullException("objectInfo", "objectInfo can't be empty");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() => StoreInfoDirect(path, objectInfo));

        }

        private void StoreInfoDirect(string path, ObjectInfo objectInfo)

        {

            try

            {

                using (var connection = GetConnection())

                using (var command = new SQLiteCommand(connection))

                {

                    if (StateExists(path, connection))

                        command.CommandText =

                            "update FileState set FileStatus= :fileStatus where FilePath = :path  ";

                    else

                    {

                        command.CommandText =

                            "INSERT INTO FileState (Id,FilePath,Checksum,Version,VersionTimeStamp,FileStatus,OverlayStatus) VALUES (:id,:path,:checksum,:version,:versionTimeStamp,:fileStatus,:overlayStatus)";

                        command.Parameters.AddWithValue("id", Guid.NewGuid());

                    }

                    command.Parameters.AddWithValue("path", path.ToLower());

                    command.Parameters.AddWithValue("checksum", objectInfo.Hash);

                    command.Parameters.AddWithValue("version", objectInfo.Version);

                    command.Parameters.AddWithValue("versionTimeStamp",

                                                    objectInfo.VersionTimestamp);

                    command.Parameters.AddWithValue("fileStatus", FileStatus.Unchanged);

                    command.Parameters.AddWithValue("overlayStatus",

                                                    FileOverlayStatus.Normal);

                    var affected = command.ExecuteNonQuery();

                    return;

                }

            }

            catch (Exception exc)

            {

                Log.Error(exc.ToString());

                throw;

            }

        }

        private bool StateExists(string filePath,SQLiteConnection connection)

        {

            using (var command = new SQLiteCommand("Select count(*) from FileState where FilePath=:path", connection))

            {

                command.Parameters.AddWithValue("path", filePath.ToLower());

                var result = command.ExecuteScalar();

                return ((long)result >= 1);

            }

        }

        public void SetFileStatus(string path, FileStatus status)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() => UpdateStatusDirect(path.ToLower(), status));

        }

        public FileStatus GetFileStatus(string path)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");

            Contract.EndContractBlock();

            using (var connection = GetConnection())

            {

                var command = new SQLiteCommand("select FileStatus from FileState where FilePath=:path", connection);

                command.Parameters.AddWithValue("path", path.ToLower());

                var s = command.ExecuteScalar();

                return (FileStatus)Convert.ToInt32(s);

            }

        }

        public void ClearFileStatus(string path)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() => DeleteDirect(path));   

        }

        private int DeleteDirect(string filePath)

        {

            using (log4net.ThreadContext.Stacks["StatusAgent"].Push("DeleteDirect"))

            {

                try

                {

                    using (var connection = GetConnection())

                    {

                        var command = new SQLiteCommand("delete from FileState where FilePath = :path",

                                                        connection);

                        command.Parameters.AddWithValue("path", filePath.ToLower());

                        var affected = command.ExecuteNonQuery();

                        return affected;

                    }

                }

                catch (Exception exc)

                {

                    Log.Error(exc.ToString());

                    throw;

                }

            }

        }

        public void UpdateFileChecksum(string path, string checksum)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");            

            Contract.EndContractBlock();

            _persistenceAgent.Post(() => FileState.UpdateChecksum(path.ToLower(), checksum));

        }

    }

}